OSU to test new tools to assess health risk from Superfund sites

Chemist Staci Simonich examines a vial containing air pollutants at her lab at OSU. (Photo by Tiffany Woods)

Biochemist Robert Tanguay checks tanks of zebrafish at his lab at OSU. (Photo by Lynn Ketchum)

CORVALLIS, Ore. – Oregon State University aims to test new technologies for measuring the toxicity of environmental chemicals to determine their health risk and see if cleaning up hazardous waste sites generates even worse chemicals.

The work will be funded by a $15.4 million, five-year grant from the National Institute of Environmental Health Sciences. The long-term goal is to improve human health by reducing exposures to toxic chemicals.

"The focus is to improve technologies for identifying and measuring the levels and toxicity of polycyclic aromatic hydrocarbons [PAHs] found at a large percentage of Superfund sites, including the Portland Harbor, and to better assess the impact of PAHs on human health," said OSU's Dave Williams, the lead scientist on the project.

The research could help local, state and federal agencies, like the U.S. Environmental Protection Agency, better understand the risk posed by PAHs, he added.

PAHs are produced when coal, gas, oil and wood are burned and even when meat is smoked or grilled. Some can cause cancer, impede normal development or harm neurological and reproductive systems, Williams said.

OSU chemists Staci Simonich and Kim Anderson will collect PAHs in the sediment, soil and water from 13 locations, including several Superfund sites. Superfund sites are abandoned or uncontrolled parcels of land or water where hazardous waste was dumped and may harm the environment or people.

At several of the sites, OSU scientists will identify which PAHs in soil and sediment get converted into other chemical compounds as a result of cleanup efforts. These remediation methods may include heating the contaminated soil and sediment, exposing it to ultraviolet light, or adding chemicals, bacteria, fungi or charcoal to it to break it down, said Simonich, a professor in the colleges of science and agricultural sciences.

"We don't know what's being formed during remediation," Simonich said. "We're going to investigate that and figure out if it is bad for human health."

Anderson will test a new device with a silicone membrane that absorbs chemicals much like a person's skin cells would. Knowing which chemicals can be absorbed by a human body is key, she said. If they can't be absorbed, then it might be safer to leave the waste in place rather than dredging it up and possibly creating even more dangerous chemicals that can indeed enter the body, she said.

Robert Tanguay, a biochemist at OSU, will test the original PAHs as well as the derivatives that formed from cleanup efforts to see how toxic they are. He'll use zebrafish, the aquatic equivalent of lab rats. Scientists use the tiny fish because they’re transparent during development, mature rapidly and share about 80 percent of their genes with humans. This allows researchers to run many tests in a short time on a huge number of subjects.

Researchers will also see if chemicals become more or less toxic when mixed together versus when they're isolated.

"We are not exposed to one chemical at a time," said Anderson, a professor in OSU's College of Agricultural Sciences. "We want to understand what the toxicity is of the mixture we're exposed to."

In partnership with Lawrence Livermore National Laboratory in California, Williams will assess how humans absorb, metabolize and eliminate extremely small doses of PAHs. This data could later be used by regulatory agencies, including the EPA, to estimate risk from exposures to PAH mixtures. These agencies have had to rely on results from animal studies that involve high dosages, said Williams, a professor in the College of Agricultural Sciences.

Interacting with communities impacted by nearby hazardous waste or exposure to PAHs is an important additional component of the university's research. So Anderson, in a partnership created by OSU public health scientist Anna Harding, will work with the Confederated Tribes of the Umatilla Indian Reservation in Oregon to address tribal concerns about environmental chemicals. Anderson will measure tribal members' exposure to PAHs from woodstoves in their homes using portable air samplers and by asking them to wear silicone wristbands that she developed to absorb atmospheric chemicals. Exposures to PAHs from eating smoked salmon will also be investigated by testing tribal members' urine to see how their bodies metabolized the PAHs.

On Fidalgo Island in Washington, Anderson will carry out a study at the Swinomish Indian Reservation, where oil refinery waste was once disposed, and at the Samish Indian Lands. She'll measure PAHs from sediment and tissues of butter clams, which tribal members' eat.

Pacific Northwest National Laboratory is a partner on the grant and an integral part of the research. Rick Corley, a toxicologist at the lab, will develop computational models to predict internal doses of biologically active PAHs in sensitive target organs of humans at different life stages – from the fetus through adulthood – under real-world exposure conditions. Katrina Waters, a computational biologist there, will provide bioinformatics support to determine linkages between exposure and disease.

In 2009, the NIEHS designated OSU as home to one of the nation’s 18 Superfund Research Programs. As part of that, it awarded the university $12.4 million to study the health risks from PAHs in the Pacific Northwest and China. More information on the program at OSU is on the Superfund Research Center website.

Since then, OSU scientists have studied fetal exposure to carcinogens and Chinese residents' cancer risk from electronic waste sites. They've also investigated the impact of air pollution on Beijing residents' health and tested the water and air along the Gulf Coast after the 2010 Deepwater Horizon oil spill. To read stories about OSU's work with PAHs, click here.

In the latest grant, researchers will collect PAHs from the following locations: